1. Field of the Invention
This invention generally relates to semiconductor manufacturing equipment and more particularly to systems and methods for the positioning and alignment of a robot and/or semiconductor materials during the manufacturing process using a reflector to reflect an image of the robot and/or semiconductor materials.
2. Description of Related Art
Semiconductor manufacturing equipment is used to process semiconductor wafers into electronic devices. Typically, in this equipment, the wafers are contained in a carrier. While in the carrier, the positions of the wafers are xe2x80x9cmappedxe2x80x9d to determine the number of wafers to be processed and the slot location of each wafer in the carrier. Wafer mapping enables the manufacturing equipment to return a processed wafer to the original slot location from which the wafer came. Returning the wafer into its original slot location in the carrier is important because equipment operators rely on slot locations to distinguish the wafers. Knowing the number of wafers contained in the carrier is also important because a computer monitoring and operating the manufacturing equipment needs to be updated as to when all the wafers in the carrier have been processed in order to alert an equipment operator to manually move the carrier out of a load lock.
Wafer mapping has been performed using laser beams. Typically, the carrier is slowly moved in a vertical direction to cross the path of a horizontally aimed laser beam. A computer keeps track of when and how many times the wafers break the beam. By knowing the distance between the slots of the carrier, the computer can determine the number of wafers and the location of each wafer in the carrier. Because each wafer in the carrier is moved to break the beam, using a laser beam to perform wafer mapping takes time. Further, detecting a cross-slotted wafer (i.e., a single wafer which occupies two slots at an angle) is difficult using a laser beam because of the limited area which a beam can cover.
Therefore, a need exists for an improved method and apparatus for monitoring the processing of semiconductor materials as well as determining the location of the materials being processed.
In accordance with the invention, a method and associated apparatus are disclosed for determining robot alignment with semiconductor wafers, wafer-like objects and other semiconductor manufacturing equipment.
In accordance with one embodiment of this invention, a method of robot automated alignment comprises viewing a robot with an arm radius, angular orientation and vertical position wherein the robot is located within a chamber; determining the arm radius, angular orientation and vertical position of the robot wherein the vertical position of the robot is determined by viewing an image reflected by a reflector located within said chamber; comparing the arm radius, angular orientation and vertical position of the robot to pre-set positions; and adjusting the arm radius, angular orientation and vertical position of the robot to the pre-set positions.
In accordance with one embodiment of this invention, a method of determining robot status via live feedback to a user comprises taking images of a robot with an arm radius, angular orientation and vertical position using a camera wherein the robot is located within a chamber and the vertical position of the robot is determined by viewing the images reflected by a reflector located within said chamber; and displaying the images on a user interface so that the user may view the robot in near real-time.
In accordance with one embodiment of this invention, a method of material tracking comprises viewing a robot with an arm radius, angular orientation and vertical position using a camera wherein the robot is located within a chamber and is holding a workpiece; determining the arm radius, angular orientation and vertical position of the robot; and determining the position of the workpiece from the arm radius, angular orientation and vertical position of the robot wherein the vertical position of the robot is determined by viewing an image reflected by a reflector located within said chamber.
In accordance with one embodiment of this invention, a method of movement error handling comprises viewing a robot with an arm radius, angular orientation and vertical position using a camera wherein the robot is located within a chamber and is holding a workpiece; determining the arm radius, angular orientation and vertical position of the robot; determining the position of the workpiece from the arm radius, angular orientation and vertical position of the robot wherein the vertical position of the robot is determined by viewing an image reflected by a reflector located within said chamber; comparing the position of the workpiece to a pre-set position; and adjusting the arm radius, angular orientation and vertical position of the robot so that the workpiece is moved to the preset position.
In accordance with one embodiment of this invention, a method of wafer mapping comprises viewing a cassette through an image of said cassette reflected by a reflector; determining the position of a wafer within a slot in the cassette; comparing the position of the wafer to a desirable position; and alerting a user if the wafer in not in the desirable position.
In accordance with one embodiment of this invention, a method of verifying the loading of material into a cassette with a plurality of notches comprises viewing the cassette using a camera wherein the positions of the notches are determined by viewing an image of the cassette reflected by a reflector to the camera; determining the positions of the notches; comparing the positions of the notches to pre-set positions; and adjusting the position of the cassette so that the notches match the pre-set positions.
In accordance with one embodiment of this invention, a robot wafer alignment tool comprises a chamber for processing of semiconductor materials; at least one camera mounted to said chamber for monitoring the processing of semiconductor materials; a computer located outside the chamber for processing images from said at least one camera; a robot located within the chamber for transporting semiconductor materials within the chamber; at least one reflector located within the chamber for reflecting at least one image from a first area within the chamber to the camera; at least one opening in the chamber to aid in the transmission of the at least one image from the chamber to the computer; and a cassette with a plurality of slots within the chamber for holding semiconductor materials.
This invention will be more fully understood in light of the following detailed description taken together with the accompanying drawings.